This invention relates generally to a check valve assembly and, more particularly, to a specially constructed dash-pot valve assembly associated with the check valve for controlling the closing rate thereof.
The use of dash-pots in conjunction with check valves, especially of the tilting disk valve type, is well known. Typically, these dash-pot valves include a spring loaded operating member or plunger arranged to be engaged by the valve member during the final closing movements thereof toward its associated valve seat. Movement of the plunger is, in turn, dampened by the resistance of a damping fluid in an hydraulic dash-pot system in which the plunger is a component part thereof. The plunger is connect to a piston adapted to be reciprocated within a cylinder having conduits interconnecting opposite ends of the cylinder to provide for the transfer of fluid from one side of the piston to the other. Throttling means, such as orifice restrictions or the like in one of the fluid transfer conduits, is provided for generating the resistance to the plunger to achieve the dampening effect. Many of these known dash-pots are bodily located exteriorly of the fluid conduit housing the check valve and are relatively complex and bulky. The known dash-pots disposed within a fluid conduit and which are submerged in the fluid are formed with narrow nozzles or passageways susceptible to plugging, often rendering them unreliable in operation. Many are provided with one-way valves in their pistons, also vulnerable to malfunction. Additionally, they are complicated in design, costly and difficult to fabricate, and provide only uniform resistance in operation.
Accordingly, it is a primary object of the present invention to obviate the above noted shortcomings by providing an improved dash-pot arrangement retarding the closing rate of an associated valve member.
It is another object of this invention to employ in the foregoing dash-pot arrangement the hydraulic principles of fluid vortex flow to progressively increase load resistance.
It is still another object of the present invention to provide an improved dash-pot arrangement which is simple and strong in construction, rugged and durable in use, inexpensive to manufacture, and which possesses the requisite dynamic response to effect progressive retardation of an associated valve member.
These and other objects, advantages, and characterizing features of this invention will become clearly apparent from the ensuing detailed description of an illustrative embodiment thereof, taken together with the accompanying drawings wherein like reference characters denote like parts throughout the various views.